US3697116A

US3697116A - Lifting device

Info

Publication number: US3697116A
Application number: US877839A
Authority: US
Inventors: Ronald Frank Carroll
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1969-11-18
Filing date: 1969-11-18
Publication date: 1972-10-10
Anticipated expiration: 1989-10-10

Abstract

A lifting device includes a lifting toe adapted to engage under an article to be lifted by the device, a top abutment adapted to engage with a top surface of the article, an actuating screw jack adapted to move said lifting toe and said top abutment towards one another and into gripping relationship with the article, and slotted grid plates presenting a plurality of recessed attachment positions one to which is located substantially over the center of gravity of the article. Where the lifting device is to be used for lifting cast concrete panels, an insert for the lower edge of the panel is used during casting of the panel to provide the panel with a recess adapted to receive said lifting toe.

Description

United States Patent Carroll [45] Oct. 10, 1972 [541' LIFTING DEVICE 3,076,674 2/1963 Anderson ..294/1o3 [72] Inventor: Ronald Frank Cam", Heme, 3,244,446 4/1966 Bopp ..294/67.l A Hempstead, England 3,275,367 9/1966 Bopp ..294/67.l A

[73] Assignee: National Research Development Corporation, London, England [22] Filed: Nov. 18, 1969 [21] Appl. No.: 877,839

[52] US. Cl ..294/103, 294/112, 294/67 AA, v 249/51 [5 1] Int. Cl. ..B66c l/00 [58] Field of Search....294/l03, 63; 249/67.l A, 112,

[56] References Cited UNITED STATES PATENTS 2,535,911 12/1950 Frame ..294/103 2,886,371 5/1959 Smock ..294/103 X 3,339,966 9/1967 Carlson ..294/112 X 3,066,968 12/1962 Brooks ..294/63 Primary Examiner-Even C. Blunk Assistant Examiner-Merle F. Maffei Att0meyCushman, Darby and Cushman ABSTRACT A lifting device includes a lifting toe adapted to engage under an article to be lifted by the device, a top abutment adapted to engage with a top surface of the article, an actuating screw jack adapted to move said lifting toe and said top abutment towards one another and into gn'pping relationship with the article, and slotted grid plates presenting a plurality of recessed attachment positions one to which is located substantially over the center of gravity of the article. Where the lifting device is to be used for lifting cast concrete panels, an insert for the lower edge of the panel is used during casting of the panel to provide the panel with a recess adapted to receive said lifting toe.

6 Claims, 9 Drawing Figures PATENTEDH T 10 me 3; 697; 1 1s SHEET 2 0F 7 FIG-.2.

PNENTEDnm 10 I972 SHEET 3 [IF 7 PATENTEDncI 10 I972 k EQM wE mm a @Qwt LIFTING DEVICE The invention relates to lifting devices and in particular to lifting devices for L-shaped panels e.g. of concrete.

According to the present invention, a lifting device includes a lifting toe adapted to engage under an article to be lifted by the device, a top abutment adapted to engage with a top surface of the article, actuating means adapted to move said lifting toe and said top abutment towards one another and into gripping relationship with the article, and attachment means adapted to present a plurality of attachment positions one of which is located substantially over the center of gravity of the article.

Where the lifting device is to be used for lifting cast concrete panels, the invention also includes a lifting assembly comprising the device of the present invention and insert means adapted to serve as an insert for the lower edge of the panel during casting of the panel thereby to provide the panel with a recess adapted to receive said lifting toe.

In order that the invention may be more fully understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings of which:

FIG. 1 shows an inside view of a mould incorporating an insert means as above referred to;

FIGS. 2 and 3 show details of the insert block and the block withdrawal means;

FIGS. 4(L) and 4(R) represent left and right portions, respectively, which join together to form a large scale view of a longitudinal section of the lifting device and the article to be lifted turned anti-clockwise through 90; 1

FIGS. 5(L) and 5(R) represent left and right portions, respectively, which join together to form a large scale view of a side elevation of the device and part of the associated lifting tackle; and

FIGS. 6(L) and 6(R) represent left and right portions, respectively, which join together to form a large scale view of a face view of the device showing a preferred form of abutment means.

Thus referring to the drawings, the device 10 comprises a leg part 12 connected with a frame 14 by a screw jack actuating means 16 controlling the separation of a lifting toe 18 on the lower end of the leg 12 and holding gates 20 at the upper end of the frame 16. Profiled grid plates 22 mounted at the top end of the frame 16 provide an attachment means presenting five attachment positions 24 to 29 for the lifting link 32 of a lifting tackle 34. The link 32 is fitted with a handle 33 whereby the position of this link may be varied at will by an operator holding the other end of the handle.

In more detail, the frame 16 comprises a head 36 from which extend two arms 38 located one on each side of the leg 12. Each arm 38 comprises an A-frame strengthened by stiffening plates 40 and struts 42. The two arms are interconnected by transverse struts 44 and a steel pad 46 which is adapted to abut with the face of the article (48) to be lifted.

At its lower end, the leg 12 is perforated by a row of holes 49 and a locking pin 50 for insertion through holes 49 is secured to the frame 16 by a length of chain 51. The adjacent end portions of the A-frames also carry guide plates 52 for the leg 12. In their middle portions the side elements are perforated by longitudinal guide slots 53, these perforated portions being strengthened by correspondingly slotted reinforcement plates 54. At their upper portions, the inner side elements carry two rows of aligned bushes 56. The outer side elements of the A-frames at this portion carry protective tubing 58 adapted to protect the device against knocks during use.

The upper ends of the A-frame sides are joined together by a steel plate 60 carrying a second abutment pad 62. A hollow square section beam 64 is secured to the plate 60 above the pad 62 and this provides a guide for the square section axles 66 of the laterally spaced holding gates 20 whereby the spacing apart of these gates can be altered if necessary to suit the article to be lifted. Abutment pads 70, 72 are also provided on those surfaces of the gates 20 and beam 64 which will engage with the article to be lifted.

The grid plates 22 are secured rigidly to the remainder of the frame 14 as will be clear from the drawings. The plates 22 extend on both sides of that part of the article 48 gripped by the device 10 and provide attachment positions24 to 29 on these two sides. This allows the lifting link 32 of lifting tackle 34 to be engaged over the center of gravity of the article 48 by a suitable choice of the attachment position in which this link is to be located. As shown in the drawings, the lifting tackle includes a shock absorber 74 and and eye 76 for engagement by a conventional lifting crane or gantry.

The leg 12 of the device is provided with a handle 77 at its lower end and at its upper end the leg is pivotally connected by pivots 78 with the female part 79 of the screw jack 16. As shown in the drawings the pivots 78 are free to slide in the slots 53 and enlarged ends 80 of the pivots prevent their accidental escape from these slots.

The male part 81 of the jack 16 is mounted for rotation in a casing part 82 of the leg 12 and carries a bevel gear 84. This meshes with a corresponding gear 86 carried on the inner end of an actuating spindle 88 which is knurled at its outer end 90.

At its upper end, the casing 82 is connected by a collared eyebolt 92 with a link 94 secured to the frame 14 by a bolted pivot pin 95 passing through one pair of opposed bushes 56, the choice of bushes depending on the desired length of the device in view of the article to be lifted.

In operation of the device above described, the device 10 is suspended from the appropriate attachment position on the plates 22 and is moved towards the article to be lifted until the pads 46, 62 abut, or nearly so, with the adjacent face of the article. During this movement, the lifting toe is held back from this face by the locking pin 50 which is located in one of the holes 49. The length of the device will have been preset with the eyebolt 92 as above described.

The operator now returns the locking pin 50 to an appropriate storage place in the frame 14 and using handle 77 he pushes the lifting toe 18 under the article to be lifted. The actuating spindle 88 is next rotated to operate the screw jack 16 and bring the lifting toe l8 and holding gates 20 into gripping relationship with the article. The lifting tackle 34 is then operated to move the article to some predetermined location and the reverse procedure to that above described is carried out to free the device from the article so that the device can be removed from the location, using lifting tackle 34, for further use.

It will be noted that the upper surface of the lifting toe 18 is specially profiled and in accordance with a preferred feature of the invention, the article 48 at its lower end provides the lifting toe 18 with a profiled recess matching the profile of toe 18. Thus in accordance with another aspect of the invention, there is provided a mould insert 100 comprising a block of which the upper part 102 is connected to the lower part 104 of the block by keyway 106. As illustrated in FIG. 1 of the drawings, this block may be mounted on the longer baseboard 108 for a mould space 22 before the associated mould member 110 is mounted in a battery and filled with concrete mix. The co-pending US. Patent application filed on the same date as the present application under the title Battery Casting of Concrete Panels and naming Mr. Cross as inventor discloses a casting process in which this block may be incorporated to provide an article with the desired lifting slot.

As will be seen from FIGS. 2 and 3, the front face 108 of the top part 102 of the block has a threaded bore 112 into which the screw part 113 of a withdrawal mechanism 114 may be screwed when the cast panel is exposed after curing. The block 100 tapers from the front face rearwardly to allow easy withdrawal of the top part 102 using withdrawal mechanism 114. The upper face of top part 110 is V-shaped when viewed from the side, the two faces of the V being inclined at 8 to the horizontal. The lower face of top part 110 inclines at 15 to horizontal.

The withdrawal mechanism 114 comprises a base part 116 which in the operative position of the mechanism is spaced from the adjacent face of the article by arms 118. In operation, the control knob 122 is first rotated to lock the screw 113 in the threaded bore 112 and thereafter rotation is by a suitable key fitted on to the square section end 124 of the screw part 1 13.

Once removed from the cast panel, the top part 110 leaves a recess matching the lifting toe 18 in profile. The toe may therefore be inserted in this recess and the actuating spindle 88 is rotated to give the device a firm grip on the panel 48 prior to removal from the mould member 110 in the manner above described.

I claim:

1. A lifting device for gripping top and bottom surfaces of an article to be lifted, comprising a frame means,

a lifting toe carried by the frame means for engaging an under surface of an article to be lifted, said lifting toe being associated with an end part of a leg member which is pivotally mounted relative to the frame means so that the lifting toe can be pivoted into and out of operative and inoperative positions in which the lifting toe is respectively in a position to engage an article to be lifted or in a position to be held clear of an article while the device is brought into position for a lifting operation,

means for moving the lifting toe between said operative and inoperative positions,

a top abutment means for engaging an upper surface of an article to be lifted,

actuating means for moving said lifting toe and said top abutment means towards one another and into gripping relationship with an article, said actuating means being operatively associated with an adjustable means carried by said device, and said adjustable means being interconnected between an upper portion of the device and a part of said leg member so that operation of the adjustable means changes the effective length of the device by moving said leg member towards or away from an upper part of said device,

means for securing said adjustable means at different locations on said upper portion of the device so as to adjust the effective length of the device, and

attachment means connected to the device for presenting a plurality of attachment positions for lifting the device, one of which positions is located substantially over the center of gravity of an article carried by the device.

2. A lifting device for gripping top and bottom surfaces of an article to be lifted, comprising a frame means,

a lifting toe carried by the frame means for engaging an under surface of an article to be lifted, said lifting toe being associated with an end part of a leg member which is pivotally mounted on a central part of the leg member so that the lifting toe can be pivoted into and out of operative and inoperative positions in which the lifting toe is respectively in a position to engage an article to be lifted or in a position to be held clear of an article while the device is brought into position for a lifting operation,

means for moving the lifting toe, relative to the remainder of the device, between said operative and inoperative positions,

a top abutment means for engaging an upper surface of an article to be lifted,

actuating means for moving said lifting toe and said top abutment means towards one another and into gripping relationship with an article, said actuating means being operatively associated with a screw jack means carried by said device, said central part of said leg member comprising one element of said screw jack means and said actuating means being adapted to operate another element of the screw jack means so that operation of the screw jack changes the effective length of the device by moving said leg member towards or away from an upper part of said device, said actuating means further comprising a spindle carrying a bevel gear which meshes with a corresponding gear on said other element of the screw jack means, and said other element being mounted for rotation in a casing part of the leg,

means for securing said casing part at different locations on said upper portion of the device so as to adjust the effective length of the device, and

3. The lifting device of claim 2, and including a body portion located between said lifting toe and said top abutment, and wherein said attachment means includes a first portion defining attachment positions to one side of said body portion and a second portion defining attachment positions to the other side of said body portion.

4; A device as claimed in claim 2 wherein the attachment means comprises grid plates presenting a lifting slot, and said attachment positions are provided by recesses spaced along the top edge of the slot.

5. A device as claimed in claim 2 wherein the top abutment comprises holding gates, and spacer means are provided for altering the separation of the gates.

6. A lifting device for gripping top and bottom surfaces of an article to be lifted, comprising a frame means,

a lifting toe carried by the frame means for engaging an under surface of an article to be lifted, said lifting toe being associated with an end part of a leg member which is pivotally mounted relative to the frame means so that the lifting toe can be pivoted into and out of operativeand inoperative positions in which the lifting toe is respectively in a position to engage an article to be lifted or in a position to be held clear of an article while the device is brought into position for a lifting operation,

a top abutment means for engaging an upper surface of an article to be lifted,

actuating means for moving said lifting toe and said top abutment means towards one another and into gripping relationship with an article, said actuating means being operatively associated with a screw jack means carried by said device, and said screw jack means being interconnected between an upper portion of the device and a part of said leg member so that operation of the screw jack changes the effective length of the device by moving said leg member towards or away from an upper part of said device,

means for securing said screw jack means at different locations on said upper portion of the device so as to adjust the effective length of the device, and

Claims

1. A lifting device for gripping top and bottom surfaces of an article to be lifted, comprising a frame means, a lifting toe carried by the frame means for engaging an under surface of an article to be lifted, said lifting toe being associated with an end part of a leg member which is pivotally mounted relative to the frame means so that the lifting toe can be pivoted into and out of operative and inoperative positions in which the lifting toe is respectively in a position to engage an article to be lifted or in a position to be held clear of an article while the device is brought into position for a lifting operation, means for moving the lifting toe between said operative and inoperative positions, a top abutment means for engaging an upper surface of an article to be lifted, actuating means for moving said lifting toe and said top abutment means towards one another and into gripping relationship with an article, said actuating means being operatively associated with an adjustable means carried by said device, and said adjustable means being interconnected between an upper portion of the device and a part of said leg member so that operation of the adjustable means changes the effective length of the device by moving said leg member towards or away from an upper part of said device, means for securing said adjustable means at different locations on said upper portion of the device so as to adjust the effective length of the device, and attachment means connected to the device for presenting a plurality of attachment positions for lifting the device, one of which positions is Located substantially over the center of gravity of an article carried by the device.

2. A lifting device for gripping top and bottom surfaces of an article to be lifted, comprising a frame means, a lifting toe carried by the frame means for engaging an under surface of an article to be lifted, said lifting toe being associated with an end part of a leg member which is pivotally mounted on a central part of the leg member so that the lifting toe can be pivoted into and out of operative and inoperative positions in which the lifting toe is respectively in a position to engage an article to be lifted or in a position to be held clear of an article while the device is brought into position for a lifting operation, means for moving the lifting toe, relative to the remainder of the device, between said operative and inoperative positions, a top abutment means for engaging an upper surface of an article to be lifted, actuating means for moving said lifting toe and said top abutment means towards one another and into gripping relationship with an article, said actuating means being operatively associated with a screw jack means carried by said device, said central part of said leg member comprising one element of said screw jack means and said actuating means being adapted to operate another element of the screw jack means so that operation of the screw jack changes the effective length of the device by moving said leg member towards or away from an upper part of said device, said actuating means further comprising a spindle carrying a bevel gear which meshes with a corresponding gear on said other element of the screw jack means, and said other element being mounted for rotation in a casing part of the leg, means for securing said casing part at different locations on said upper portion of the device so as to adjust the effective length of the device, and attachment means connected to the device for presenting a plurality of attachment positions for lifting the device, one of which positions is located substantially over the center of gravity of an article carried by the device.

4. A device as claimed in claim 2 wherein the attachment means comprises grid plates presenting a lifting slot, and said attachment positions are provided by recesses spaced along the top edge of the slot.

6. A lifting device for gripping top and bottom surfaces of an article to be lifted, comprising a frame means, a lifting toe carried by the frame means for engaging an under surface of an article to be lifted, said lifting toe being associated with an end part of a leg member which is pivotally mounted relative to the frame means so that the lifting toe can be pivoted into and out of operative and inoperative positions in which the lifting toe is respectively in a position to engage an article to be lifted or in a position to be held clear of an article while the device is brought into position for a lifting operation, means for moving the lifting toe between said operative and inoperative positions, a top abutment means for engaging an upper surface of an article to be lifted, actuating means for moving said lifting toe and said top abutment means towards one another and into gripping relationship with an article, said actuating means being operatively associated with a screw jack means carried by said device, and said screw jack means being interconnected between an upper portion of the device and a part of said leg member so that operation of the screw jack changeS the effective length of the device by moving said leg member towards or away from an upper part of said device, means for securing said screw jack means at different locations on said upper portion of the device so as to adjust the effective length of the device, and attachment means connected to the device for presenting a plurality of attachment positions for lifting the device, one of which positions is located substantially over the center of gravity of an article carried by the device.